Figure 16. Distributicn of fish in pens, experiments U7-50. All experiments 

 started with 1,000 fish in pen No. 1 (far left). In controls, gates between 

 pens lifted for indicated period, then lowered. Tests, same except sounds of 

 indicated durations and frequencies (cycles per second) applied at indicated 

 location while gates up. Numbers and dark bars show distribution of fish after 

 gates lowered. 



19 



